The invention relates to manufacturing management, and particularly to a manufacturing management system and method for cross-site lot handling.
In semiconductor manufacturing, several manufacturing layers including FAB (Fabrication), CP (Circuit Probe), BP (Bumping), CF (Color Filter), ASM (Assembly), FT (Final Test), and others are required to the complete manufacturing. Additionally, several manufacturing sites may be provided for each manufacturing layer. Conventionally, each manufacturing site is controlled by one MES. FIG. 1 is a schematic diagram illustrating a conventional manufacturing procedure. In this procedure, the manufacturing site FAB 112 in manufacturing layer FAB 110 is controlled by MES 111, CP 122 in manufacturing layer CP 120 is controlled by MES 121, and FT 130 in manufacturing layer FT 130 is controlled by MES 131. One wafer may go through several manufacturing layers to become final products. After a lot is completed from manufacturing site FAB 112, the lot information is then transmitted from MES 111 and created in MES 121.
Future lot handling, such as Future Hold, is important and fundamental for quality control in a foundry MES (Manufacturing Execution System). Future Hold is a fundamental function for holding wafers or lots at a specific operational stage or step for inspection or further special manufacturing instruction. After the wafer scheduling process is complete and released to the MES, Future Hold can be registered by users or by the MES. The prerequisite for future lot handling, however, is that wafers should be first created in the MES. There is no way to perform future lot handling for wafers which have not been created in the MES.
In the CP manufacturing layer, for example, wafers typically come from the FAB manufacturing layer with a short cycle time. Conventionally, CP users cannot register a lot handling record for these wafers prior to creation thereof in the CP MES. Since the cycle time is short and there is no sufficient lead time to set a lot handling record, client special inspection instructions may easily go unheeded, resulting in damage to product quality, and raises client complaints. Further, since the operation is performed manually, it is manpower and time-consuming.
Furthermore, some clients may have their own manufacturing plans after they send orders to the supplier. Setting a lot handling record is a trigger point for their manufacturing plans. Conventionally, clients have to continuously monitor whether their wafers have been released to production or not. Only after wafers are released to production can the lot handling record be registered. The monitoring process for clients is inefficient.